Rotary engine.



PATENTED JAN. e, 1903. M. E. KNIGHT. ROTARYENGINE.

APPLICATION FILED JUNE 4, 1902.

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' PATENTEDJAN.-6,1903. M. E. KNIGHT. 'ROTARY ENGIWNE. APPLICATION FILED JUNE 4,-1902.,

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No. 717,869. PATENTED JAN. 6, 1903.

' M. E. KNIGHT.

ROTARY ENGINE APPLIGATIONJILBD JUNE 4, 1902.

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UNITED STATES PATENT OFFICE.

MARGARET E. KNIGHT, OF SOUTH FRAMINGHAM, MASSACHUSETTS.

ROTARY ENGINE.

SPECIFICATION forming part of Letters Patent No. 717,869, dated January 6, 1903.

Application filed June 4, 1902.

To ttZZ whom it vita/y concern:

Be it known that I, MARGARET E. KNIGHT, a citizen of the United States of America, residing at South Framingham, in the county of Middlesex and Commonwealth of Massachusetts, have invented certain Improvements in Rotary Engines, of which the following is aspecification,

The improvements relate particularly to the construction and arrangement of pistons and their abutmen ts for rotary engines, either single acting orcompound, and the combination of two or. more. pistons in a manner to obviate vibration of the engine when in operation; and the invention consists in hanging a plurality of pistons upon bearings eccentric to the center of the piston-chamber. When two pistons are used, they are arranged with their eccentricity diametrically opposite to each other,and when three are nsed the two end pistons are hung with the eccentricitydiametrically oppositeto the middle piston, and the steam-pressure area of the middle piston and its centrifugal force when in motion should be substantially equal to that of the two end pistons.

The invention further consists in making the so'called steam-abutment of a plate oi metal and attaching its upper edge securely in the enginecasting above the cylinder, while the lower edge projects downward into a slot formed in each piston and in which it slides as the pistons revolve on their eccentric bearings about the engine-shaft.

In the accompanying drawings, Figure l is a vertical central longitudinal section of the engine. Fig. 2 is a vertical cross section through the high-pressure cylinder on line 2 2, Fig. 1, viewed from the left; Fig. 3 is a verticalcross-section through the low-pressure cylinder on line 3 3, Fig. 1, viewed from the right. Figs. 4.- to 10 illustrate the piston in seven differentpositions, showing its relation to the abutment at each forty-five degrees of one revolution. Figs. 4 and 8, 5 and 9, 6 and 10, respectively, show the piston in diametrically opposite positions, while Fig. '1 shows the piston in a position-midway between that shown in Figs. 6 and 8, or fortyfive degrees from each.

Referring to the drawings, A is the outer shell or casing, which encompasses the whole Serial No. 110,236. (No model.)

engine; A, a jacket of some material which is a non-conductor of heat.

B is an inner casing which constitutes the cylinders or steam-chambers M M N N N the valve-chamber, and the walls for steam,- passages D D, leading from the valve to the several steam-chambers.

In Figs. 1 and 3, O is a space between the casing A and B, which serves as a passage for exhaust-steam, and is connected by a pipe E with a vacuum-chamber. (Not shown.) This steam-filled space 0 also serves as a steamjacket for the engine.

F is the steam-inlet.

For the purpose of preventing vibration and lateral racking motion of the engine and What is known as torque of the engineshaft I have provided two high-pressure cylinders M M, with their pistons m m counterpoised by hanging them upon eccentrics on the shaft H in diametrically opposite positions, and three low-pressure cylinders N N N with their pistons counterpoised byhanging the pistons 01? n of the two end cylinders N N upon corresponding eccentrics on the shaft H and the piston 97. of the middle cylinder N upon an eccentric on the shaft diametrically opposite to the other two. The pistons m m n n n of the engine are cylindrical in form and are hung upon eccentrics h, keyed to the shaft H.

The steam-abutment, as illustrated, consists of a continuous metal plate 0, secured at its upper end in the middle portion B of the upper part of the steam-cylinder casting or engine-frame, while the lower edge of the plate 0 extends down into slots 0', cut longitudinally in the several piston-cylinders and substantially radially to their axes. At the upper ends of these slots near the peripher of the pistons semicircular grooves 0 are formed upon each side of the plate-abutment, and in these grooves semicircular gibs or bearing-pieces o are placed. The slots are made wider at their inner edges toward the center of the cylinders to accommodate the swing of the lower end of the abutment. As the pistons circulate within their respective cylinders they reciprocate upon the lower end of the abutment O, which is caused to slide in'and out of the slots 0 and between the pieces 0 upon which the pistons oscillate.

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The plate 0 may be divided into as many portions as there are pistons in the engine, if desired. The motion of these pistons upon the eccentrics h within their respective cylinders is akin to that of the strap of a valve eccentric on a reciprocating engine-shaft. In this case, however, the motive power is applied to the piston and forces it around within the engine-cylinder, and in this operation the pistons act upon the eccentrics keyed to the shaft, the eccentrics serving as cranks to turn the shaft and impart motion to the driving-wheel of the engine.

The multichambered valve is the same as the valve shown in the drawings and de scribed in the specification of my application, Serial No. 103,512. In the same vertical plane as the pipe F an annular passage G is formed in the casing around the valve V. This valve is provided with a hand-wheel V, on the rim of which live notches are cut to indicate the different positions to which the valve should be turned to start the engine in either direction with live steam supplied to all of the cylinders or to direct the live steam from the high-pressure cylinders to the lowpressure cylinders when it is desired'to employ double expansion of the steam. Also an index-mark is made upon a convenient part of the frame by which to set the valve in the desired position. Referring to the valve in its closed position, as shown in the drawings, the lower chamber R has a port which is coincident with the passage G, and therefore is always supplied with live steam. The chamber R also has-a port S, which opens into a passage leading to the cylinders M M, and a port S, which opens into a passage leading to the cylinders N N N when the valve is turned to its first position in either direction, and then live steam will be directed to all of the cylinders. The portin the portion of the chamber R through which live steam is supplied to the cylinders N is much narrower than the port which supplies steam to the cylinders M, and consequently live steam will be directed to the cylinders N only when the valve is in its first position. The chamber U, Fig. 1, extends to the right in two branches U U down beneath a chamber W and upon either side of the narrowed chamber R, as seen in Fig. 3, and each of these chambers U is provided with a port S The chamber U has two other branches U U, extending to the left upon either side of the chamber R and beneath a'chamber T. These latter branches U U and the chamber T are respectively provided with steam-ports u M2 and 6 as shown in Fig. 2. The chamber T connects with a chamber T, which opens into the atmosphere,

and the chamber W is open at the right-hand end and connects with the exhaust-passage C. It also has a long wide port to, which registers with the exhaust-passages of the cylinders N N N on the one side or the other, depending upon the direction of rotation of the pistons when the engine is in operation. When the valve is turned to the second position, live steam is still supplied to the cylinders M from the chamber R. The port 1& of one of the branches U then registers with the supply-passages to the cylinders N and the port w of the chamber W with the exhaustpassages of the cylinders N. Then the en gineis operated by double expansion of steam.

It will be observed that by making the middle piston N equal in weight and eccentricity to that of the two end pistons N N and arranging the eccentricity of these latter two pistons diametrically opposite to the eccentricity of the middle piston N not only is all unevenness in the running of the engine prevented, but also all torque of the engine-shaft, which objectionable feature exists in engines provided with heavy pistons where two only are used, although arranged to counterbalance one another.

Lubricant is supplied to the interior of the several steam-cylinders from chambers L at each end of the engine through a hole longitudinally of the shaft H, froinwhich hole openings 1 are made coincident with each cylinder and also with each chamber L.

I claim- 1. In a rotary engine the combination of two cylindrical pistons, eccentrically counterpoised upon a single driving-shaft, a 1ongitudinal slot in each piston radial to its axis, and a single plate-abutment for the pistons, one edge of which abutment is secured in the casting of the steam-cylinder and the other edge of which projects into the slots of the several pistons, which reciprocate thereon when the engine is in motion.

2. In a rotary engine the combination of three cylindrical pistons, upon a single shaft, with the two end pistons eccentrically counterpoised'by the middle piston, a longitudinal slot in each piston radial to its axis, and an abutment for the three pistons, one edge of which abutment is secured in the casting of the steam 7 cylinder and the other edge of which projects into the slots of the several pistons which reciprocate thereon when the pistons revolve within their cylinders.

MARGARET E. KNIGHT.

Witnesses:

A. L. ROBINSON, R. L. ROBERTS. 

